Jon: Thanks. That article looks pretty interesting in giving an overview of the thinking that went into FBW (Fly-By-Wire). There's always more than one way to skin a cat so I'm not surprised David Carter that Airbus has a difference. But it points out that each type of plane will have its own system, hence users, in this case Pilots, Co-Pilots and Flight Engineers (if indeed, flight engineers still exist) will get indoctrinated into the system they fly with. Clearly, part of the problem that got Boeing into its current mess was their desire to take a very successful airplane designed in the 1960s into the new era with a minimum of retraining. But they clearly over-reached. In fairness I think they thought they cold do this safely and unfortunately it turned out they did not succeed. They have to bear considerable responsibility.

I have not read Airframe but I will get it on my reading list. I'll probably print out the document Jon found and alternate Crichton's work with the FBW paper, which looks like fun.